1. Technical Field
The embodiments herein generally relate to communication systems, and more particularly to the field of de-interleaving interleaved data in orthogonal frequency division multiplexing (OFDM) communication systems, such as integrated services digital broadcasting terrestrial (ISDB-T) systems.
2. Description of the Related Art
In various communication systems, data gets distorted by channel impairments like fading, multipath prorogations, interference, Doppler Effect, etc. In case of small errors the altered bits can be corrected easily by using error correction codes, but in case of burst errors, higher numbers of data bits are altered and the transmitted data typically cannot be recovered completely. Time interleaving is performed by spreading coded symbols in time before transmission to protect data from burst errors.
OFDM based communication systems, such as ISDB-T use time interleaving to randomize modulated symbol data in the time domain in order to ensure robustness against fading interference and channel impairments. ISDB-T is used to provide many services such as data broadcasting, high definition television (HDTV), interactive TV, mobile applications, etc. ISDB-T was designed keeping in mind a mobile reception. De-interleaving requires a large memory due to the deinterleaver delay buffer and therefore, in general, the deinterleaver designs are random access memory (RAM) based. In RAM based designs, implementation of large number of memory pointers may lead to large number of counters. Such counters are generally implemented as flip-flops leading to a larger deinterleaver area and thereby resulting in greater power consumption. Hence, it would be desirable to reduce the deinterleaver area and reduce the complexity of deinterleaver design.